When George Washington took the oath of office as the country’s first president in 1789, he placed his hand upon the Bible while speaking those solemn 35 words required by the Constitution, beginning a tradition that has come to define the pomp and circumstance of Inauguration Day.

And though the act of swearing upon a Bible held significance at the time, the particular book he chose did not.

It was, historians say, an afterthought. Organizers had simply forgotten to bring one, so they grabbed the closest holy book they could find — a nearby Masonic lodge’s altar Bible — and Washington made his promise.

But in the two centuries since then, the act of choosing an inaugural Bible — or Bibles — has become far more symbolic.

On Wednesday, President-elect Donald Trump announced his choices: a Bible his mother gifted him in 1955 when he graduated from Presbyterian Sunday school and the one President Abraham Lincoln used at his inauguration.